Answer:
7. x = 4
8. x = 10
Step-by-step explanation:
7. The angles are equal to each other so you can do
40 = 12x - 8
48 = 12x
4 = x
8. The angles add up to be 180 degrees so you can combine them and set them equal to 180
6x + 12x = 180
18x = 180
x = 10
